TOEFL Reading: ETS-TOEFL阅读机经 - M57WY71D440PO3XVL$

Which of the following is mentioned in paragraph 3 in the shedding of large branches by oaks on calm, hot afternoons? A. The development of a brittle zone at the base of the branches B. The enlargement of cracks in the branches due to heat C. The rise of sudden bursts of wind that snap off decayed wood D. The seasonal need to propagate new trees